Hi Cystone, I am unsure of what you are asking, but I can refer you to the Shell LNG Dual Mixed Refrigerant (DMR), this new design is about to be revamped into a split train system. This allows two seperate systems to run in tandem together or in a maintainence situation one system can be shut down totally seperate to the other. These benefits are required for a live continous operating plant which is what Shell's new Floating LNG is intending to achieve. It is not uncommon for dual or split train systems to appear in any industry be it oil, gas,car manufacture or even mining processing, once again it is there to add efficiency in both maintainence and continuing product output.